No one likes to use the bathroom right after another guy, because it is full of bad smell. It takes a tiresome period of time waiting for fresh air again in the bathroom. What a terrible waiting.
Nowadays, a bathroom is always fitted with a ventilating system on the ceiling or with other known means, but this does not get rid of the bad smells right away. Though the government of the Republic of China has approved of a kind flush toilet which is regarded as able to take away the bad smell (by official document No: 6222256), as a patented article with its necessary fittings, yet it works inside of the water tank, involving drafting openings, a drafting chamber, and the flush stool together formed into a ventilating system with the drafter, by the drafter's driving power sending the bad smell from the stool to the outside of the building. This kind of flush toilet operates by a spring for switching the power on and off. The bad smell being sent outside of the building pollutes in the community of a housing area. On the other hand, this kind of structure would never be able to eliminate the bad smell completely.